From Minneapolis to New York City, nation faces frigid New Year's Eve and start to 2018

(This story, first published late Wednesday afternoon, was updated Thursday morning.)

Relentless and punishing, repeated blasts of cold air will continue surging into the Lower 48 through the first week of the New Year. Only the western United States will be spared.

This cold is likely to be the nation’s most extreme since February 2015 and, over a long duration, will produce dangerously low temperatures and wind chills over large portions of both the central and eastern United States.

Temperature some 15 to 30 degrees lower than normal will grip much of the eastern two-thirds of the nation up to seven to 10 more days. Some parts of the north central United States could see temperatures an astonishing 40 to 50 degrees colder than normal this weekend.

Temperature difference from normal as forecast by GFS model Thursday through Wednesday.

On the morning of New Year’s Day, the National Weather Service predicts the nation’s average low temperature to hover around 10 degrees, with about a third of locations below zero.

Low temperatures forecast by National Weather Service Jan. 1. (WeatherBell.com)

These temperatures, compared to normal, will be the coldest in the world.

The coldest weather (relative to average) will be positioned right over North America through at least the next 7-days...

The piercing cold over the Upper Midwest and Great Lakes is pouring into the Northeast, where the National Weather Service predicts record-cold high temperatures Thursday. Highs are only expected to reach 10 to 15 degrees in Boston, about 20 in New York and 25 in Washington.

Forecast high temperatures from the National Weather Service on Thursday are expected to be near record lows for the date. (WeatherBell.com)

The pinnacle of this unforgiving cold snap is likely to occur between this weekend and the first few days of the New Year, progressing from the Dakotas to the Northeast. On Saturday, some parts of eastern Montana, the Dakotas and northern Minnesota may see air temperatures crash to minus-40 degrees, and wind chills to minus-50 or lower. High temperatures may not exceed minus-10 Saturday, which would threaten some records.

On Saturday and Sunday, Minneapolis is forecast to have highs of only about minus-5, with lows near minus-15. Wind chills will be considerably lower, as cold as minus-30. Chicago may see its highs stuck in the single digits both Saturday and New Year’s Day.

In the East, 2018 may start off even colder than the close of 2017. The American and European model predict New York City will ring in the New Year with an air temperature near 10 degrees and wind chills of zero to minus-5. This would rank among the coldest ball drops in the Big Apple in recorded history. The last time it was so cold was in 1962; 1917 marked the coldest ball drop, when the air temperature was a mere 1 degree.

European model forecast of New York City temperature at 1 a.m. Jan 1. (WeatherBell.com)

Subzero wind chills are likely to cover enormous territory New Year’s Day — extending as far as south as Oklahoma, Arkansas and the central Appalachians.

Wind chill forecast from GFS model at 7 a.m New Year’s Day.

Just how cold will your city be? Here is the European modeling system’s (ensemble mean) forecast for the coldest day between Dec. 30 and Jan. 2:

Minneapolis: Sunday. High: Minus-4, low: minus-16

Milwaukee: Monday. High: 8, low: minus-2

St. Louis: Monday. High: 14, low: 0

Oklahoma City: Monday. High: 23, low: 12

Dallas: Monday. High: 31, low: 23

Chicago: Monday. High: 5, low: minus-10

Detroit: Sunday and Monday. High: 10, low: minus-9

Cleveland: Monday. High: 9, low: 0

Indianapolis: Monday. High: 5, low: minus-9

Memphis: Monday. High: 26, low: 14

Boston: Monday. High: 9, low: minus-2

New York: Monday. High: 17, low: 5

Pittsburgh: Monday. High: 15, low: 2

Washington: Monday. High: 22, low: 12

Raleigh, N.C.: Tuesday. High: 28, low: 19

Atlanta: Tuesday. High: 33, low: 20

Note that while we are confident it will be extremely cold, forecasts are likely to change some over the coming days. Models have tended to predict somewhat colder temperatures than reality this year at long lead times. But even if these predicted temperatures are a little colder than what actually materializes, it will still be bone-chilling cold.

As the first week of the New Year progresses, temperatures are forecast to remain well below normal in the central and eastern United States. Some new model information suggests the most extreme Arctic blast yet could arrive Wednesday and Thursday (Jan. 4-5) before the cold finally starts to ease around January 8 or 9.

Summary of 00z Euro model: a brutally cold Canadian high drifts thru for the New Year. Then the #PolarVortex arrives to finish the job for Jan 4-5th ... historical level cold. pic.twitter.com/0BFsY2aGIm

Jason SamenowJason Samenow is The Washington Post’s weather editor and Capital Weather Gang's chief meteorologist. He earned a master's degree in atmospheric science and spent 10 years as a climate change science analyst for the U.S. government. He holds the Digital Seal of Approval from the National Weather Association. Follow